Machine for boring articles



MACHINE FOR BORING ARTICLES Filed Nov. 12, 1948 4 Sheets-Sheet l Fiehl lNVENTOi? [WALD 14. APP

fiWE/WM ATTORNEY Jan. 20, 1953 E. A. ARP

MACHINE FOR @ORING ARTICLES 4 Sheets-Sheet 2 Filed NOV. 12, 1948 IN l/E N 70/? [WALD A. APP 3e. WBMM A 7' TOP/VF Y Jan. 20, 1953 E. A. ARP

MACHINE FOR BORING ARTICLES 4 heets-Sheet :5

Filed Nov. 12, 1948 P v w i m MMMW 2 Br a Jan. 20, 1953 E. A. ARP

MACHINE FOR BORING ARTICLES 4 Sheets-Sheet 4 Filed Nov. 12, 1948 PP Y MMWN M/ l/E N WALD/1.

Patented Jan. 20, 1953 UNITED STATES: PATENT OFFICE Ewald A.'Arp,.;Minneapolis, Minn., assignor to Tobin-Arp Manufacturing Company, Minne- 1 *apolis, Minn., a corporation of Minnesota Application November 12, 1948, Serial No. 59,727

6 Claims. I 1

' This invention has relation to a machine which has been devised to be especially useful for boring the bearings of articles such, for example, as the bearings of connecting rods for wrist pins, etc. An object'of the invention is to provide a machine for boringbearings which will be of novel and improved construction and designed to perform its intended service in new and improved .manner.

chine adjustableclamping units for supporting articles bearings of which are to be boredwhich will'zbe-of 'simple,-practical, eflicient, new and improved construction.

. V 'Withtheabove objects inview, Jas. ;well.,as others which will appear as the specification proceeds, the invention comprises the construction,

arrangement and combination of parts "as now tobe fully-described and'as hereinafter to be specifically'claimed; it being understood that the disclosure herein is merely illustrative and intended in :noway in a limiting sense, changes in details ofconstruction and, arrangement of parts being permissible as longas within the spirit of the invention and the scope of the claims which follow.

In the accompanying drawings forming a part of this specification,

Fig. 1 is a top plan view of a machine made according to the invention, a part of the frame of the machine being broken away;

Fig. 2 is an enlarged fragmentary elevational view disclosing parts of the machine as they would appear from the bottom of the sheet in Fig. l, the frame of said machine in section and an adjustable clamping unit of the machine in section, taken substantially on line 22 in Fi 3;

Fig. 3 is a vertical sectional view, taken as on line 3-3 in Fig. 2, with parts omitted;

Fig. 4 is a detail sectional view, taken on line 4:4-in:Fig.'3;j

t'irFig 5 is ar'sectional view, taken substantially on line 55 in Fig. 3 and on a reduced scale, detailing features of an adjustable clamping unit of themachine, the view also showing a supporting unit ofsaid machine inside elevation; and Fig. 6 is an enlarged sectional view, taken on line 6-6 in Fig. l.

A frame 10 of the machineis constituted as a rectilinear slab of rigid material, and can be supported in any suitable and convenient manner, as, for example, as a part of a table, desirably so that the rectilinear slab will be in a horizontal plane; I I a v 1 Spaced apart, parallel boring bar supporting units, indicated II and I2, respectively, are situated upon the flat upper surface I3 of the frame Ill for slidably adjustable movement in direction toward-and away from each other, and said supporting units I I and I2 include self-alining bearings, represented I4 and I 5, respectively, which can be of construction as disclosed in my pending application Serial No. 44,442, for Self-Alining Bearing, filed August 16, 1948, adapted to-be situated in alined relation in a single, desirably horizontal; plane to be capable of selectively receiving a boring bar with cutting tool (not shown), or a locating rod or mandrel I6, as in Fig. 1'. The supporting units II and I2 are keyed to' the frame I0, as at I26, for slight rockin movement in a horizontal plane.

The boring bar supporting unit I I is'constituted as an elongated rectilinear memberdisposed in perpendicular relation to the frame !il, as well 'as' in' perpendicular relation to a boring bar with cutting tool, or to a locating rod or mandrel, such as I6, when situated in the self-alining bearings I4 and I5. A fiat lower surface I? of said boring bar supporting unit II rests upon the flat upper surface I3 of said frame It for slidable movement thereover toward and away from the boring bar supporting unit i2, and lower portions of the boring bar supporting unit II are cut away to provide spaced apart, elongated slots I8, contiguous with the flat lower surface I? and parallel to a locating rod Or mandrel or to a boring bar when in said self-alining bearings I4 and I5, including upwardly facing shoulders I9 for a purpose to be made plain. Additionally, upper portions of the boring bar supporting unit II include spaced apart, horizontally disposed, transversely extending guideways 20, at the opposite sides of the self-alining bearing I 4 in spaced relation thereto, contiguous at their inner and outer --ends with flat interior and exterior surfaces, indicated 2I and 22, respectively, of said boring bar supporting unit II and parallel with a locating 3 rod or mandrel or a boring bar when in the selfalining bearings I4 and I5, as well as parallel with the frame Ill. The flat interior and exterior surfaces 2| and 22 are perpendicular to a locating rod or mandrel or a boring bar when in said self-alining bearings I4 and I5 and to said frame I0.

The boring bar supporting unit I2 is constituted as an elongated rectilinear member disposed in perpendicular relation to the frame II), as well as in perpendicular relation to a locating rod .or mandrel, or to a boring bar, when situated in the self-alining bearings I4 and I5. A flat lower surface 23 of said boring bar supporting unit 12 is in adjacent or contiguous relation to the flat upper surface of said frame I6, and lower portions of the boring bar supporting unit I2 are cut away to provide spaced apart slots 24, contiguous with said flat lower surface 23 and parallel to a locate ing rod or mandrel, or to a boring bar, when in said self-alining bearings I4 and I 5, which house supporting rollers 25 resting upon said flat upper surface I3 for rolling or slidin movement of the boring bar supporting unit I2 toward and away from the boring bar supporting unit II. Also upper portions of the boring bar supporting unit I2 include spaced apart, horizontally disposed, transversely extending guideways 26, at the pposite sides of the self-alining bearing I in spaced relation thereto, contiguous at their inner d and outer ends with flat interior and exterior surfaces, indicated 21 and 28, respectively, of said boring bar support I2 and parallel with a locating rod or mandrel or a boring bar when in the selfalining bearings I 4 and I5, as Well as parallel with the frame I6. The flat interior and exterior surfaces 21 and 28 are disposed in parallel relation to the fiat interior and exterior surfaces 2I and 22.

The guideways 20, and 26, 26 are in a single horizontal plane, and guideways 26, 26 and 20,

26 of the different supporting units I I and I2 are in alinement.

The machine includes a pair of duplicate selfadjusting clamping units, each represented 29, one of which is mounted upon the supporting unit I I and the other of which is mounted upon the supporting unit I2. The clamping units 29 are situated between the supporting units I I and I2. Their construction and the manner of their detachable association and assembly with said supporting units will be hereinafter described.

Spaced apart supporting brackets, each designated 36, situated at opposite sides of the selfalining bearing I4 in spaced relation thereto and at the side of the supporting unit I I opposite the supporting unit I2, are rigidly secured, as at 3!, upon the frame I6, and each supporting bracket 36 rigidly carries, as at 32, a horizontal cylinder 33 adjacent the outer end of and with which the guideway 26 at the corresponding side of said self-alining bearing I4 is concentrically alined.

Each horizontal cylinder 33 fixedly supports, as at 34, a hollow head 35 adjacent the supporting unit II, and slidably supports, as at 36, a piston 31, at the side of the hollow head 35 opposite said supporting unit I I. A space within each cylinder 33, between the corresponding hollow head 35 and piston 31, is denoted 38, and a port 39 through said corresponding hollow head 35 is contiguous at its inner end with a flexible hose 40 and at its outer end with the space 38. Each'flexible hose 40 passes through and is secured in an opening 4| through its corresponding horizontal cylinder 33. The inner end of each flexible hose is sealed shut by the corresponding hollow head 35, and a port 42 in each flexible hose is contiguous with the port 39 through said corresponding hollow head. Each piston 31 supports a, neck 43, and packing surrounding the neck and engaged against the body of the corresponding piston, a well as against the interior surface of the corresponding cylinder 33, is represented 44. Fluid under pressure within the spaces 38 of the cylinders 33 is adapted to cause the pistons 3! to be forcibly moved away from the hollow heads 35, to the right in Figs. 1 and 6 of the drawings, and said pistons 31 will be free for movement toward said hollow heads 35, to the left in said Figs. 1 to 6, upon relief of the fluid under pressure.

Each piston 31 rigidly centrally supports, as at 45, a connecting plug 46 slidably mounted, as at 41, in the hollow interior 48 of the corresponding head 35, and the inner end portion of each connecting plug 46 is disposed in the corresponding guideway 20 with the flat exterior surface 22 of the supporting unit II in contiguous or adjacent relation to the interior surfaces of the hollow heads 35, about as disclosed in Figs. 1 and 6. A packing between an outer end portion of each connecting plug 46 and an interior surface of the corresponding hollow head 35 is indicated 49, an annular flange rigid with the inner end of each connecting plug 46 and situated in the inner end portion of the corresponding guideway 20 is denoted 50, and a compression coil spring 5I in the hollow interior 48 of each head 35, in surrounding relation to the corresponding connecting plug .46 and having it opposite ends engaged against the corresponding hollow head 35 and annular flange 50, normally urges said corresponding connecting plug 46 and the corresponding piston 31 inwardly, in direction toward the supporting unit I I, to the left in said Figs. 1 and 6. The construction and arrangement are such that the pistons 31 will cause the connecting plugs .46 to be moved outwardly, away from the supporting unit I I, in response to application of fluid under pressure to the spaces 36 of the cylinders 33, against resilient action of the compression coil springs 5|, and said compression coil springs will react upon relief of pressure in said cylinders 33 to cause said pistons 31 and connecting plugs 46 to be moved inwardly, toward said supporting unit'II.

Each of the guideways 26 through the supporting unit I2 removably supports a bushing 52, and a connecting rod 53 slidably disposed in each bushing 52 has an end portion thereof, in spaced relation to said supporting unit I2, secured, as at 54, in the inner end portion of the connecting plug 46 at the corresponding side of the selfalining bearing I4. The connecting rods 53 are ad-iustably assembled, through the instrumentality of the bushings 52, with the supporting unit I 2 to the end that said supporting unit I 2 can be initially set closer to or farther from the supporting unit I I, depending upon the size of an article the bearing of which is to be bored. Each connecting rod 53 is in alined relation with its corresponding connecting plug 46, and the outer end portion of each connecting rod includes longitudinally spaced grooves 55 extending the full circumference of the connecting rod. Fixing screws 56 in the supporting unit I2 are for detachably locking the bushings 52 in the guideways 26, and a ball 5'! in a radial slot 58 in each bushing 52 is adapted to be selectively removably situated in the different grooves 55 of the corresponding connecting rod 53 thus to secure said corresponding connecting rod in fixed relation to the bushing. A manipulating knob on the free, outer end of each connecting rod 53, adjacent the outer end of the corresponding bushing 52, is denoted 59. The supporting unit I2 will be initially set on the frame I at a distance from the supporting brackets 30, 30 so that the clamping units 29, 29 will become engaged with opposite surfaces of an article a boring of which is to be bored in response to'actuation of the pistons 31 in direction away from the supporting unit H in the manner as hereinbefore set forth. It will be apparent that the supporting unit I2 will be forcibly moved toward said supporting unit I I, through the instrumentality of the connecting plugs 46 and the connecting rods 53, in response tooutward movement of said pistons 31, and with relief of-pressure inthe spaces 38, the compression coil springs 5| will return said supporting unit I2 to the position at which initially set.

The boring bar supporting unit II is adapted to be locked down against the fiat upper surface I3 of the frame I0 through the instrumentality of vertically disposed locking elements 60 slidably mounted, as at 6I, in the "frame III. The upper end portion of each locking element 60 is disposed above the flat upper surface I3 of said frame III in an elongated slot I8, and a compression coil spring 62, upon each locking element 60 between a collar 63 thereon and said flat upper surface I3, normally urges the corresponding locking element 60 upwardly. A neck 64 with head 65 rigid with the upper end of each locking element 60 lies in the elongated slot I8 at the corresponding end of the supportingunit II with said head 65 above and said neck 64 between upwardly facing shoulders I9 of said supporting unit I I, and said compression coil springs 62'normally retain the locking elements 69 in position to permit the supporting unit II to be released from the frame I0.

A vertical cylinder 66, in surroundingrelation to the lower end portion of each vertically disposed'locking element 60 and rigid with the lower surface of the frame I0, slidably supports a piston 6I fixed, as at 68, upon said vertically-disposed locking element. A space within each cylinder 66, above the corresponding piston 61, is denoted 69, and a port leading to each space 69 is represented I0. Each'piston 61 has a neck II, and packing surrounding the neck and engaged against the body of the corresponding piston, as g 'well as against the interior surface of the corresponding cylinder 66, is

represented I2. Fluid under pressure, applied through a flexible hose (not shown), within the spaces 69 of the cylinders 66 is adapted to cause the pistons 61 to be "forcibly moved downwardly, and said pistons will be free for upward movement upon relief of the fluid under pressure. The construction and arrangement aresuch that the heads 65 will be moved downwardly with downward movement of the pistons 61, against resilient action of the compression coil springs 62, to be grasped against the shoulders I9, and said compression coil springs. 62 will react upon relief of pressure in said cylinders 66 to cause the heads 65 of the locking elements to be released from said shoulders I9.v

The self-adjusting clamping units 29, 29 are disposed in spaced, parallel relation, andeach of said clamping units includes a retainer member I3 to be detachably assembled with one of the supporting units, II or I2, as-the case may be.

,Each retainer member I3 is constituted as an annular element 14 having a flat exterior surface I5, adapted to be engaged against the flat ing frame 8L interior surfacey2l or 21,-as the case may be, of the corresponding supporting unit, and an atare upon the posts I8, the flat exterior surfaces of the annular elements of the retainer members and the flat interior surfaces of the supporting units will be in engagement. An annular flange 19 upon each annular element I4, adjacent the corresponding attaching element I6, is adapted to retain the corresponding retainer member I3 against movement in a horizontal plane relative to the corresponding supporting unit.

An exterior bearing race supporting frame of each self-adjusting clamping unit 29 is designated 89, and an interior bearing race supporting frame of each clamping unit is represented 8|.

Each exterior bearing race supporting frame 88 is constituted as an annular body 82, rigidly fitted and secured, as at 88, within and to the corresponding-retainer member I3, and a partspherical annular bearing 84 situated at the side of thecorresponding annular body 52 adjacent the corresponding interior bearing race support- Each annular bearing 84 is disposed in parallel relation to the flat exterior surface of. the corresponding retainer member 13 and provides an annular, interiorly facing bearing surface 85 which is of partspherical configuration.

Each interior bearing race supporting frame 8! is constituted as an annular body 88 and an annular flange 8i in surrounding, perpendicular relation to an intermediate portion of said annular body 86. An annular bearing 88 rigidly secured upon and about the portion of each annular body 86 at the side of the corresponding annular flange 9? adjacent the corresponding exterior bearing race supporting frame 89, against said corresponding annular flange 8?, provides an exteriorly facing bearing surface 89 which is of part-spherical configuration and is disposed interiorly of and in spaced relation to the interi orly facing bearing surface 85 of the corresponding annular bearing 68. Each annular bearing 88 is in concentric relation to the corresponding annular bearing 89 and each exteriorly facing bearing surface 89 is in concentric relation to the corresponding interiorly facing bearing surface 85.

A conical retainer fixedly secured about and against the exteriorly facing bearing surface 69 of each annular bearing 88 is denoted 99, and balls within openings through each conical retainer 96 and engaged with the corresponding interiorly and exteriorly facing bearings surfaces 85 and 89 are indicated iii.

The ball bearing construction and arrangement as illustrated and described permits rocking movement of the interior bearing race support-= ing frame 9I upon the exterior bearing race supporting frame 89 in the instance of each adjustable clamping unit 29, and each interior bearing race supporting frame 8! is supported upon its corresponding exterior bearing race supporting frame 68 by clips 82 in such manner as to offer no interference to relative rocking movement of said interior and exterior bearing. race supporting frames. Each clip 92 includes a verti- '7 cal body portion 93 rigidly secured, as at .94, to the annular flange 81 of the interior bearing race supporting frame 8| of the corresponding adjustable clamping unit and a part-spherical wing portion 95 upon the corresponding part-spherical annular bearing 84. The wing portion of one of the clips 92 includes an elongated slot 96 in its outer end in which a pivot pin 91, supported upon and extending outwardly'from the annular hearing 84 of the exterior bearingrace supporting frame 80 of the corresponding adjustable clamping unit, is situated. The construction and arrangement are such that each clip 92 is supported upon the corresponding annular bearing 84 to be free to have both rocking and bodily movement toward and away from said corresponding annular bearing.

An exterior flexible sheath suitably and conveniently connected between the retaining member 13 and the annular flange .81 of each adjustable clamping unit29 is represented 98, and an interior flexible sheath suitably and conveniently connected between the annular body 82 and the annular body 86 of each adjustable clamping unit is indicated 99.

A portion of the annular body 86 of the interior bearing race supporting frame 8| at the side of the annular flange 81 opposite the annular bearing 88 provides, in the instance of each selfadjusting clamping unit 29, an externally facing cylindrical bearing surface I in concentric relation -tosaid annular body 86, and an annular element IOI, integral or rigid with each annular flange 81 at the side thereof opposite the corresponding exterior bearing race supporting frame 80 and in spaced, surrounding, concentric relation to the corresponding externally facing cylindrical bearing surface I00, deflnes, together with said annular flange 81 and bearing surface I00, an annular concavity I02.

An annular disc I03 in each concavity I02 adjacent the corresponding annular flange 81, supported upon the corresponding externally facing bearing surface I00 for rotative movement, constitutes a combination gear and actuator of each clamping unit 29. Stated otherwise, each annular disc, or combination gear and actuator, I03 integrally includes equally spaced gear teeth I04 upon its periphery and equally spaced camming slots I05 in its surface opposite the corresponding annular flange 81. In the disclosure as made, there are three camming slots I05 spaced at 120 degrees apart, each camming slot curves smoothly from an outer toward an inner portion of the corresponding annular disc, and the camming slots in each annular disc bear precisely the same relation to its true center.

The end of the annular body 86 of each interior bearing race supporting frame 8| adjacent the corresponding externally facing bearing surface I00, opposite the corresponding annular bearing 88, is cut away to provide spaced apart, radially extending T-slots I06 each defining spaced apart, oppositely disposed, parallel, radially extending ribs I01, I01 situated in contiguous relation with a flat interior surface I00 of said annular body 86, as well as in parallel relation to the corresponding annular flange 81. In the disclosure as made, there are three sets of spaced apart, oppositely disposed, parallel, radially extending ribs I01, I01 spaced at 120' degrees apart.

The free end of each annular element IOI, spaced interiorly from the corresponding annular flange 81, is cut away to provide spaced apart,

radially extending T-slots 1.09, in radially alined relation to the T-slots' I06, each defining spaced apart, oppositely disposed, parallel, radially .extending ri-bs .I I0, H0 situated in contiguous relation with a flat interior surface III of said ,annular element IOI as well as in parallel relation to the corresponding annular flange 81. As shown, there are three sets of spaced apart, oppositely disposed, parallel, radially extending ribs IIO, H0, and the spaced apart, oppositely disposed ribs of each set upon each annular element I01 are in radial alinement with the spaced apart, oppositely disposed ribs of a set upon the corresponding annular body 86. Also, the flat interior surfaces I00 and III of the annular body .86 and the annular element IE3], respectiyely, of each ,clampingunit 29 lie in .a single plane paral lel to the annular flange 81 of the corresponding interior bearing surface supporting frame 81.

Each clamping unit incorporates three different sets of radially zalin d, nner an ou er slots, and each set of T-slots I06, I09 slidably supports a radially adjustable clamping member or block II-2. Each clamping member or block I 12 includes lon itudinally extending slots H3, H3 in its opposite side edges in which the corresponding spaced apart ribs I01, I01 and I10, I I0 are ly fitt thu t r n er th cla pin members or blocks slidably adjustable radially of the corresponding interior bearing race supporting frame .81.. Said clamping members or blocks are adapted to beadjusted radially of the corresponding clamping unit, selectively inwardly or outwardly, in response to rotative movement of the correspOnding annular disc I03, and to this end a camrning element I I4 rigidly fixed in an outer nd portion of e ch c am n m mbe o b ck IIZ includes an extension .II5 snugly, slidably situated in a corresponding camming slot I05 A cover for ach .of the annular concavities I 02 is constituted as segmental plates H6, between adjacent clamping members or blocks II 2,. As shown, each segmental plate H6 has its opposite side ed es snugly, slidably fitted, as at I I1, in the longitudinally extending slots II3 of the next adjacent clamping members or blocks, the outer and inner circumferential surfaces of each segmental plate are, respectively, contiguous with an internal cylindrical surface of the corresponding annular element IOI and the externally facing cylindrical bearing surface I 00 of the corresponding annular body 86, and each segmental plate is in spaced, parallel relation to the annular disc I03 of the corresponding clamping unit.

A pinion for rota ing each annular disc I03 is i nated H8. Each pinion I 8 is fix dly supported on an intermediate portion of a spindle II 9 having one of its'end portions rotatably mounted, as at I20, in the annular flange 81 of the corresponding interior bearing race supporting frame BI and its other end portion rotatably mounted, as at I2I, in an adjacent segmental plate IIB. There is a pinion H8 in mesh with ear teeth I04 of each annular disc I03, and an end of each spindle II9 projects beyond the segmental plate IIB in which mounted and fixedly supports a knurled hand piece I22 for accomplishing manual rotation .of the corresponding pinion. A tension washer upon each spindle -I I9 between the corresponding hand piece I22 and segmental plate I I6 is denoted I23. Each knurled hand piece I22 can be rotatably manipulated to cause the corresponding annular disc I03 to be rotated, through the instrum'entality of the corresponding pinion IIBand gear teeth I04, thus to cause the correspoding clamping members or blocks I I2 to be simultaneously adjusted inwardly and outwardly, and the construction and arrangement are such that all of the clamping members or blocks I I2 of each clamping unit will be moved to equal extent or degree in response to rotatable adjustment of the corresponding annular disc I03.

When the self-adjusting clamping units 29, 29 are assembled with the bearing bar supporting units II and I2, the clamping members or blocks I I2 of the different self-adjusting clamping units are in opposed relation, and flat interior surfaces I24 of the clamping members or blocks of each clamping unit lie in a single plane parallel with the plane of the annular flange 81 of the correspondin clamping unit.

In the accomplishment of practical operation of the machine, the borin bar supporting units I! and I2 will be set up on the frame ID in spaced relation to each other a distance sufficient to permit the self-adjusting clamping units 29, 29 to be supported in spaced relation upon and between saidsupporting units, in the manner as set forth, an article, such as I25, a bearing of which is to be rebored will be placed between the clamping units, and a locating rod or mandrel will be inserted in and through the self-alining bearing I4, the clamping unit upon the supporting unit II, said article, the clamping unit upon thelsupporting unit I2 and the self-alining bearing I5, as the locating rod or mandrel I8 is disclosed situated in Fig. 1 of the drawings. Thereafter, the supporting units will be actuated in the manner as hereinbefore described to cause the clamping units 29 to grasp oppositely disposed surfaces of the article.

Supposing the article a bearing of which is to be bored to be of about the construction as in the disclosure, said article will be situated so that its longitudinal axis is disposed in a plane parallel to the frame II] with its open ends adjacent the clamping units 29, 29, and the clamping members or blocks I I2 of the different clamping units will be adjusted to be in longitudinally alined relation to said article and clear'of its bearing to be rebored. With said article and clamping members or blocks'so relatively situated, fluid under pressure will be applied to the spaces 59 of the vertical cylinders 68 and to the spaces 38 of the horizontal cylinders 33. Fluid under pressure applied to said spaces 59 will cause the supporting unit II to be secured down against the frame Ii! in the manner as set forth, and in response to fluid under pressure applied to said spaces 38 the supporting unit I2 will be forcibly moved toward said supporting unit II, also in the manner as described. The flat interior surfaces i24 of the clamping members or blocks II2 will engage the opposite ends of the article a bearing of which is to be bored, in spaced relation to the bearing. Upon application of force to the clamping members or blocks causing them to be pressed against the article, the interior bearing race supporting frame 8| of each clamping unit will be capable of rocking in universal direction relative to its corresponding exterior bearing race supporting frame 80 with the result that said clamping members or blocks will exert retaining pressure against opposed surfaces of articles having bearings to be rebored in direction longitudinally of the articles and apply no force tending to impart rocking movement to the articles. The construction and arrangement will be such that the partspherical bearing surfaces 85 and 89, which are concentric to each other, also are concentric, in the instance of each clamping unit 29, to an axis of rotation for the corresponding interior bearing race supporting frame BI in the longitudinal axis of a locating rod or mandrel when supported in the machine, as well as in the plane of the flat interior surfaces I24 of the clamping members or blocks I I2 of the corresponding clamping unit. Thus with rocking movement of the interior hearing race supporting frames 8| relative to the exterior bearing race supporting frames 80, said clamping members or blocks I I2 will rotate about fixed axes which are both in the longitudinal axis of a locating rod or mandrel and in the plane of the flat interior surfaces I24, and there will be no shifting movement of the axis of rotation for the clamping members or blocks as would be the case were saidaxis of rotation not so situated. Stated otherwise, the construction and arrangement will be such that the clamping members or blocks I I2 will remain at unvaryin distance from the axes of rotation of the interior bearing race supporting frames BI with rockin movement of said interior bearing race supporting frames. Thus any selected location in any of the flat interior surfaces I24 will bear unchanged relation to the axis of rotation of the corresponding interior bearing .race supporting frame no matter to What position it may be rocked, and the axis of rotation for the flat interior surfaces I2 5 of the clamping members or blocks II2 of each clamping unit fixedly remains in the plane of said flat interior surfaces, as well as at the longitudinal axis of a locating rod or mandrel when supporting an article to be bored.

, Pressure of fluid in the spaces 38 of the cylinders 33 and in the spaces 69 of the cylinders 66 will be relieved when an article is to be removed from the machine, and another article the bearing of which is to be rebored can be located in the machine by repetition of the operations hereinbefore described.

It will be understood of course that the locating rod or mandrel I6 will be removed from an article having a bearing to be rebored after said article is set up in the machine, and a boring bar with cutting tool set up in the bearings of the supporting units II and I2 and actuated to accomplish a reboring operation upon the bearing of the article.

What is claimed is:

1-. In a machine of the character described, a frame, spaced apart, parallel supporting units mounted on said frame for movement toward and away from each other, alined bearings upon said supporting units for removably receiving a boring bar locatin element for insertion through an article to be bored while situated between said supporting units, spaced, apart, self-adjusting clamping units upon said supporting units each comprised as an outer annular bearing support upon one of said supporting units and having a first annular, part-spherical bearing surface at its inner side and in concentric relation to said alined bearings, an inner annular bearing support having a second annular, part-sperical hearing surface at its outer side and in spaced, concentric relation to said first annular, part-spherical bearing surface, means mounting the inner annular bearing support of each of said clamping units upon the outer annular bearing support thereof and interconnecting said inner and outer annular bearing supports for relative universal rocking movement, clamping surfaces upon and disposed inwardly of each of said inner annular bearing supports, said first and second annular, part-spherical bearing surfaces of each of said clamping units being concentric to an axis of rdtation for the inner annular bearing support of the corresponding clamping unit in the longitudinal axis of a boring bar locating element when in said alined bearings and also in the plane of the clamping surfaces upon said inner annular bearing support, said clamping surfaces of the inner annular bearing supports of the different clamping units being in substantially parallel, oppositely disposed relation and said clamping units being situated between said supporting units and said article and each having an opening dis-' posed interiorly of the correspondin first and second annular, part-spherical bearing surfaces for passage of said boring bar locating element, and means for actuating said supporting units toward each other to cause said clamping surfaces upon said inner annular bearing supports to be engaged against oppositely disposed surfaces of said article.

2. In a machine of the character described, a frame, spaced apart, parallel supporting units mounted on said frame for movement toward and away from each other, alined bearings upon said supporting units for removably receiving a boring bar locating element for insertion through an article to be bored while situated between said supporting units, spaced apart, self-adjusting clamping units upon said supporting units each comprised as an outer annular bearing support upon one of said supporting units and having a first annulanpart-spherical bearing surface at its inner side and in concentric relation to said alined bearings, an inner annular bearing support having a second annular, part-spherical bearing surface at its outer side and in spaced, concentric relation to said first annular, partspherical bearingsurface, means mounting the inner annular bearing support of each of said clamping units upon the outer annular bearing support thereof and interconnecting said inner and outer annular bearing supports for relative universal rocking movement, radially adjustable clamping members upon each of said inner annular bearing supports, a clamping surface upon each of said clamping members disposed inwardly of the corresponding inner annular bearing support, said first and second annular, partspherical bearing surfaces of each of said clamping units being concentric to an axis of rotation for the inner annular bearing support of the corresponding clamping unit in the longitudinal axis of a boring bar locating element when in said alined bearings and also in the plane of the clamping surfaces of the clamping members upon said inner annular bearing supports, saidclamping surfaces being in substantially parallel, op-

positely disposed relation and said clamping units being situated between said supporting units and said article and each having an open-' ing disposed interiorly of the corresponding first and second annular, part-spherical bearing surfaces for passage of said boring bar locating element, and means for actuating said supporting units toward each other .to cause said clamping surfaces upon said inner annular bearing supports to be engaged against oppositely disposed surfaces of said article.

3. The combination as specified in claim 2, and means for accomplishing radial adjustment of said clamping members.

4. In a machine of the character described, a frame, a supporting unit on said frame, a bearing upon said supporting unit for removably receiving a boring bar locating element for insertion through an article to be bored, a selfad-justing clamping unit comprised as an outer annular bearing support upon said supporting unit and having a first annular part-spherical bearing surface at its inner side and in concentric relation to said bearing, an inner annular bearing support having a second annular, art-spherical bearing surface at its outer side and in spaced, concentric relation to said first annular, partspherical bearing surface, means mounting the inner annular bearing support upon the outer annular bearing support and interconnecting said inner and outer annular bearing supports for relative universal rocking movement, and clamping surfaces upon and disposed inwardly of said inner annular bearing support, said first and second annular, part-spherical bearing sur-' faces being concentric to an axis of rotation for said inner annular bearing support in the longitudinal axis of a boring bar locating element when in said bearing and also in the plane of said clamping surfaces.

5. The combination as specified in claim 4 wherein said clamping surfaces are upon clamping members assembled with said inner annular bearing support for radial adjustment.

6. The combination as specified in claim 5, and meansfor accomplishing radial adjustment of said clamping members.

EWALD A. ARP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,077,652 Sutch Nov. 4, 1913 1,582,639 Cullen Apr. 2'7, 1926 2,445,147 Meunier July 13, 1948 

